Air cleaner



A. A. BULL AIR CLEANER Filed Apil 30. 1925 ATTORNEY.

i Pa-tentedijan. l26, 1932 ATEUR A. BULL, OF DETROIT, MICHIGAN" AIR CLEANER Application filed .April 30, 1925. Serial N0. 26,8601

carburetor and thence into the engine-cylinv ders.

The present invention is an improved construction in whichfasuspended dome and a standpipe are used to require the air to turn twice before it passes into the carburetor. This has two purposes,-one to add another turning movement and thereby more thoroughly assure lthe elimination of allsus-- pended matter, and secondly to ,interpose a standpipe through the center of the cleaner to prevent the dust and suspended matter' thrown out in a centrifugal'action, from' rising at the center of the cleaner and being drawn into the suction pipe. These and other features will be more thoroughlyD described in the specification following.

In the drawings:

Fig. l is avertical showing of an air; cleaner which can be connected up Withthe carburetor of an internal combustion engine, and showing in Fig. 1 a the carburetor and engine on a reduced scale.

Fig. 2 is an elevation of the cast vane unit.

Fig. 3-is a plan view of the cleaner. Fig. 4 is a section on the line 4 4 of Fig. 1.

'ai is preferably a drawn shell or may be a casting. A vane unit, preferably a diecasting, has a plurality of vanes b. This unit is pressed into the'upper end of the shell. The

. vanes give the air entering a swirling action andcause the air to swirl-around on the inl action tliowsout the heavy particles by cen- ?trifugal force. They drop by gravity, and

forces the suspended matter down to the bottom corner of the shell below the hood 0,

which is interposed to prevent the accumulat- .fside ofthe wall of the shell. This swirling ing dust from rising back up as it is caught in the trap in the bottom. Discharge ports d are provided, and have inclined baiiles e interposed in the direction of the centrifugal air stream for the purpose of intercepting and directing the suspended matter out through the ports at the bottom.

An air cleaner of the above general construction is shown in my priorapplication Serial No. 729,866, filed August 4, 1924, which application disclosedin part the subject matter of this application.

In my improved structure I interpose in the center of the shell a standpipe. This standpipe therefore has a physical action in restraining the detachment of any of the suspended matter in a centrifugal current.

To that extent the same is a considerable aid in confining all the suspended matter to the centrifugal action and cause it to be forced down intol the trap at the bottom and finally discharged by gravity and the slight accumulated air pressure. l

Furthermore, this standpipe presents still 1 a further barrier in the path of suspended n matter entering the suction pipe. By interposing the dome f at the top of the shell, and having this suspended over and extending beyond the mouth of the standpipe, but slightly spaced therefrom, the air current in being drawn into the carburetor iscaused to make a second turn in the cleaner. Every turn that the air is constrained to inake facilitates the separating action, as all suspended matter tends to separate by the inertia action, 85

wherever the air column is caused to make a sharp turn. It will be noted that the bottom flange or rim of the dome considerably extends beyond the diameter of the opening. of the mouth of the suction pipe and causes the suspended matter, if any, to drop before it can be drawn over the rim of the standpipe into the suction line.

I have shown my air cleaner' operating in a vertical position. This is the most advantageous position for the device to function in, but measurably good results can be accomplished by turning the device so that its axis liesto the horizontal. In a vertical position the device is not only better situated to perform its normal function, but it also lends itself nicely to the attachment to the so-called discharge port is located at or in the vicinityof the end of the cleaner casing, opposite the vanes. The dust separation takes place by the centrifugal action resulting from the 2 0 helix or whirl of air, and also from thereversing action in directing the flow. The inertia of the helical air current serves tobuild up an end thrust at -the dust discharge opening, which counteracts the incoming pressure so as to either so greatly reduce this 'or actually overcome it as to permit the separated matter, such as the dust, to be discharged directly to the atmosphere, the discharge being o ei'ectedeither by reason ofthe inertial of the counter'vailing pressure on the inside of the cleaner, even when theV only source of pressure is the sucton of the engine and thevmospheric pressure. In order to make thls helical column of air eilicacious in producing n end thrust it is necessary that the velocity of the air be not greatly reduced. Consequent'? ly in my air cleaner it will be seen that the passageways'at or adjacent the end of the dome 'f do not greatly exceed,` if they do exceed, the cross-sectional area of the air -outlet tube or standpipe. This is very limportant for it results in the utilization of maximum air velocity in the helix without .45 material restriction. This distinguishes my air cleaner from the devices of the prior art, such as the Weck 'Patent'548,490, of *October 22, 1,895, wherein the cross-sectional area of the air helix at or adjacent the discharge end ofthe vanes is several times the crosssectional area ofthe air outlet. I therefore disclaimsuch a structure as shown in the Weck patent, 'and confine. such claims where these limitations are introduced vto an air cleaner in which the cross-sectional area of I the air helix" at or'adjacent the discharge en d' 65 Itwill be noted from the drawings and swirling dust, or else'at times by an actual.

the pitch ofthe vanes that there is considerable' inclination of the vanes from the axial line. This is,roughly, if a straight line were drawn from the upper edge of the Vvane to the lower edge, but these valles are somewhat curved and near the lower edge the vanes are very much more inclined to the vertical, roughly approximating o from the axial line. The exact inclination is not essential, but itis highly desirable and effective to give a considerable inclination'tob 'the Yvane so that if continued in a helix they would make substantially one or more revolutions before they reachthe dust outlet end of the casing. 'I his gives a whirling stream which is much more eifective to generate a countervailing pressure on the closed end as counterdistinguished to a stream which has very little inclination to the axial line. In l outlet pipe entrance for the purpose of permitting the reversal of the air currents and hence the separation of the suspended matter both by gravity and by centrifugal forcedue to the'helix of air.' These features are very. desirable in effectively separating dust and discharging it directly to the atmosphere in a cleaner which can depend only on the sucflion of the engine for whatever air blast it as. r

The dust discharge slot or passageway is formed by the struck in baillev c, which leaves the final dust outlet port d. However, the

Vdust discharge slot, orthe dust ou let passage, or by what other name it e deslgnated,\is really that space below the baffle e, together with the final dust outlet port d. This baille c is slightly offset from the wall from which it is struck and the free edge of this baille,together with the edge of the 4linal onglet port, forms 'an opening which faces in a direction substantially reverse to the direction in which theswirling air cur' rent is traveling at this point. It also lies across the air streamat this point. It is therefore calculated to intercept the air stream and. skim the dust particles out of the air stream and they are thus enabled to discharge by their own inertia, even in the face of a slight differential of pressure on the outside of this outlet. The ele'ctivemouth or o ening of this dust discharge passage is de ned 1n the claims 1n various ways, faclng 1n a tangential line, or facing substantially reverse to the direction of travel of the swirling 'air stream, or arranged to 'have a wall cutting directly into the air stream. `These are all intended to define this Varrangement of' the .opening into lthe discharge passage, which or more relatively restricted outlet ports normally open for the discharge of the suspended matter by means of the pressure built up bythe swirling action, the said shell piovided also at this last `mentioned end with suction means and means within the shell for bending the air away from said discharge port or ports and then bending the same in a direction toward said port or ports as the the dust particles directed thereto by the iair is drawn into the suction outlet.

2. In an air cleaner, a shell adapted to be vertically or horizontally positioned and prof vided at one end with a closure having one or more discharge ports, the opposite end of the shell being open and provided with centrifugally acting'stationary means longitudinally inclined in the direction of the axis for permitting the entry of the air and for simul- -taneously giving the same. an axially swirling action, and one or more baiiles located ad- 'jacent the discharge ports for'intercepting the swirling air and suspended matter, and directing the same out vof the ports and into the atmosphere.

-3. In an air cleaner, the combination of a Yshell `provided with an end inclined 'upwardly I. stricted outlet and the suction connection, said hood serving for entrapping the dust at the center and provided with one or more vdischarge portsI alongthe outside of the saidend and further provided withl a hood sc particles separated from the air.

5. vAnair .cleaner comprising as a* unit, anv outer shell having an open end and a s ub- 4stimtially-closed end, provided .with a restricted dust outlet to the atmosphere', a conduit'positioned centrally-of said closed end and extending into'said shell and' provided 'with suction means, a stationary dome positionedin said o n end inaxial ali en't with-said conduit and terminating a jacent the upper end ofsaid conduit, andstationary vanes positioned between said dome and shell and acting in combination with said dome for .giving the incoming air a swirling motion axially and outwardly in a spiral path past the upper end of said conduit and toward the periphery ofthe closed end of said shell, and a dust trap surrounding said conduit and ex.

tending outwardly adjacent the walls of the shell for entrapping the dust particles separated from the downwardly and outwardly directed air current.

6. An air cleaner of the type designed to separate dust particles by centrifugal action, comprising av shell with a closed end and a conduit positioned centrally of said kclosed end and extending inwardly into said shellv and provided with suction means, and an annular balile extending outwardly and axially towards the closed end of said shell for forming a chamber for receiving and entrapping centrifugal action of the air.

' 7. An air -cleaner comprising acylindrical shell having an open end and a closed end, a conduit positioned centrally of said closed end and extending inwardly into said shell, and provided with suction. means, a dome positioned at the said open end having walls substantially parallel with the walls of the shell, the extremities of said walls of'said dome terminating adjacent the upper end of the conduit and being outwardly flared to direct the incoming air axially past the 'con'- duit opening, and means positioned in the s ace between the dome and shell walls for irecting the incoming air axially and outwardly with a swirling action for separating` the dust particles therefrom. y

8. An air cleaner,hav'ing in combination,

.a shell having an air opening at one end and closed atfthe opposite end except for one or more openings to the `atmosphere of very limited size, centrifugally acting means longitudinally inclined in the direction of the axis and positionedfnear the opening for giving the incoming air a swirling motion by simply guiding it into a spiral path, thereby separating the dust and tending to expel the vseparated dust through such small opening, said shellI provided with an air outlet having suction means in connection therewith, and

a h ood between the restricted dust outlet and said air outlet forming a dust trap to retain the collected diist until discharged' by the,

pressure built uplby the momentum of said swirling air.

forY th incoming air-and having stationary centrifugally acting means longitudinally inclined in the direction'of the axis at such end for bending the incoming air current and di' recting it into a swirl and having at the opposite end of the shell a relativelyrestricted outlet port normally open for the discharge ica of the suspended rmatter by means of the youtlet port as the air pressure built up by the swirling action, the

said Shell provided also with suction means provided 'with suction means, a dome positioned at the said open end having walls sub-s stantially'paiallel with the wallspf the shell, the extremities of said walls of said dome ter minating adjacent the end of the conduit and being outwardly flared to direct the incoming air axially past the conduit opening, and

.means positioned in the space between the dome and shell'walls for directing the incoming air axially and outwardly with a swirling action for separating the vdust particles therefrom.

11. An air cleaner for use in combination with suction creating apparatus such as an internal combustion engine, etc., having in combination a casing having an air cleaning chamber, helically arranged stationary guiding vanesfor bending and lguiding the air toy be cleaned, which air is' taken into one end of said chamber, said guiding varies forming said air into a helical stream by the pull of the suction apparatus and directing such helical stream toward the opposite end in a screwlike swirl, an outlet pipe connected with said vchamber'. `axially and arranged for reversing the How of said air,'said casing being closedagainst discharge of any substantial amount of separated matter to the atmosphere beyond the .varies save for a dust discharge passage I or passages to thel atmosphere'locatedat or in the vicinit of the` end opposite the entrance end, said yust passage being relatively smallI and arranged to have a Wall cutting directly into the swirling air stream and being so'pil'oportioned and located that in conjunction. v

stream it is adapted to discharge the dust directly to the l outside atmosphere from the linterior of the chamber when the pressure in with the thrust of the'swirl of said helical portions of said chamber is sub-atmospheric and capableof'eiecting said discharge solely by the force suction pull.

12. An air cleaner. for use in combination with suction creating apparatus such 'as' internal combustion engines, etc., having in combination a .casing having an air-cleaning chamber, longitudinally inclined stationary 4varies at one end ofthe-casing for forming the incoming air into a helix, an air outlet air outlet.

the casing opposite the vanes, said outlet pipe arranged for reversing the air flow, said casin being closed against discharge of any su tantial amount of separated matter-to the atmosphere on the delivery side of the vanes.

save for a relatively small dust discharge slot or slots directly to the atmosphere located onlyat or in the vicinity of the end of the casing opposite the 'guiding vanes, the discharge slot having its effective mouth facing in anA Y approximately tangentialline and contrary to the direction of' travel of the Vair stream and lying-across the line of travel of `the'swirling air current at this point, said slot thereby arranged to intercept the swirling air cur rent, the said guiding vanes forming passageways whose total cross-sectional area at their discharge end doesv not greatly exceed the cross-sectional area of theair outlet pipe,

whereby the velocity of the screw-like air.l

stream is not materially lowered and the thrust of such airstream coupledwith a relatively small dust outlet port so located serves to counteract the outside atmospheric pressure at the dust outlet slot to permit discharge ofseparated dust or other matter directly to the .atmosphere even when the only pressurecreating means is the suction through the 14.' The combination claimed in claim 1131 in which the dust discharge passage is forme by a portion of the Wall of the casing offset,

from its normal plane.

specified inclaim 12,;- 5 l In testimony whereof I have aiixed my l l signature.

ARTHUR A. BULL.

generated in the air swirl by the v Viin izo 

